Dual-input molecular logic circuits for sensitive and simultaneous sensing of multiple microRNAs from tumor cells

Abstract

In this work, simple molecular logic circuits have been constructed by using two microRNAs (miRNAs) and the amplified fluorescent signals, respectively, as the inputs and outputs, and the application of such molecular circuits for simultaneous detection of multiple miRNA targets from tumor cells with high sensitivity has also been demonstrated. Synchronous binding of the two miRNA input targets with the fluorescently quenched double stem-loop probes leads to the unfolding of the stem-loop structure and the recovery of the fluorescence. Such fluorescence recovery is significantly enhanced via the duplex DNA fuel-assisted target recycling amplification through the toehold-mediated strand displacement reaction, thereby resulting in the realization of an “AND” gate operation and simultaneous and sensitive detection of the two miRNA targets. By assigning different inputs, an “INHIBIT” gate operation can also be achieved. In addition, the established method can be further employed to simultaneously monitor two miRNAs from low numbers of tumor cells, suggesting the potential application of the molecular circuits for disease diagnosis.